Operating mechanism for electric circuit breakers



. 4, 1949- R. J. BASKERVILLE OPERATING MECHANISM FOR ELECTRIC CIRCUIT BREAKES Filed Dec. 9, 1944 Inventor. Ralph xlBasker ville,

l-lis Atoorne g.

Patented Jan. 4, 1949 OPERATING MECHANISM FOR ELECTRIC CIRCUIT BREAKERS Ralph J. Baskerville, Merwood Bark, Pa., assignmto General Electric Company, a corporation of New York Application December 9, 1944, Serial No...567,468-

3 Claims. (01. 200-456) My invention relates to operating mechanisms 1 I for electric circuit breakers, and more particularly to operating mechanisms of the trip-free typev wherein the means tobe actuated may be instantly released either during or after the pe riod of actuation independently of the actuating or motive means.

She operation of apparatus such as electric circuit breakers or switches by trip-free mechanisms is an old and well known practice. Such operating mechanisms were usually modified in accordance with the particular type of circuit breaker to which they were applied and means for relating the operating mechanisms to various devices such as opening springs or buffing and damping devices had to be provided. Needless to say such arrangements Were complicated, expensive, and did not lend themselves Well to general application without elaborate changes and the like.

It is therefore the principal object of my invention to provide a new and improved unitary operating mechanism for an electric switch or circuit breaker comprising a trip-free type of mechanism including opening spring means and buffer devices.

It is another object of my invention to provide a new and improved operating mechanism of the trip-free type for electric switches or circuit breakers which is simple and compact, of sturdy construction, and simple to manufacture.

Further objects and advantages of my invention will become apparent as the following description proceeds and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention reference may be had to the accompanying drawing in which Fig. 1 is an elevational view partly in section of an electric circuit breaker employing the operating mechanism of my invention; Fig. 2 is an enlarged view of a portion of Fig. 1 illustrating the operating mechanism at a predetermined point during the closing operation of the electric circuit breaker; Fig. 3 is a view similar to Fig. 2 showing the operating mechanism in the position which it assumes with the associated circuit breaker in the fully open position; and Fig. 4 is an enlarged sectional view taken on the line 4--4 of Fig. 3, assuming that no parts of Fig.3 are cut away.

Although the operating mechanism of my invention is applicable to various forms of electric circuit breakers and switches, I have chosen to til illustrate it specifically as applied to circuit breakers of the type disclosed in Linde Patents 2,293,513 and 2,335,068, granted August 18, .1942 and November 23, 1943, respectively, and as signed tothe same assignee as the present application. This circuit breaker is generally indicated in Fig. 1 by the numeral I and comprises a pair of relatively movable contacts 2 and 3. The contact 3 is a movable contact and is supported on an arml rotatable about a pivot 5. The operating mechanism of my invention is mounted in a housing 6 closely. associated with the housing [of the circuit breaker I. A suitable link 8 interconnects pivotally mounted arm 4 with the operating mechanism of my invention, generally indicated at 9.

The motive means for operating mechanisms for electric, circuit breakers, as will be under stood by those skilled in the art, might be a fluid motor, electric motor, solenoid or any suitable means. For the purpose of illustrating my invention the motive means of the operating mechanism 9 of my invention is illustrated as-a solenoid l0 comprising a vertically movable armature ll attached to an. operating plunger l2. Solenoid I0, as illustrated in the drawings, is mounted beneath the trip-free linkage of the operating'mechanismwhich is supported between a pair of parallel side plates l3 "and [4, best shown in Fig. 4. Side plates I 3 and 14 in efiect form a housing. for-the trip-free linkage and associated parts of my invention and preferably the solenoid I0 is supported from these parallel plates or a base plate l5 associated therewith. Base plate I5 is provided with an opening I6 through which plunger I2 may extend.

The thrust-transmitting linkage providing the trip-free mechanism comprises the operating.

crank ll, pivotally mounted at 18 between plates I3 and I4. One end of operating crank I! is pivotally connected as at l9 to link 8. The other end of operating crank I1 is curved and is connected by pivotal means as indicated at 20 to a collapsible or floating linkage, generally indicated at 2|. This linkage 2| is very similar to that disclosedand claimed in Thumim' Patent 1,827,626, granted October 13, 1931, and assigned to the same assignee as the present application.

Floating or collapsible linkage 2| comprises the link 22 and the link 23 pivotally related by a shaft having an extension 24. A suitable roller 25 is also mounted on the shaft having the extension 24. The free end of link 22 is connected with the curved end of operating crank I1 as is indicated at 20. The'free end of link 23 is served from the drawings that links 22 and 23 form a toggle With the shaft having the extension 24 as the knee joint thereof The plunger I2 is adapted iniitsgupward movement to engage the roller' 2-5 positioned at theknee of the toggle and upward movement thereof to the position indicated in Fig. 2 straightens the toggle com prising links 22 and 23 and causes rotation-of operating crank Win a counter-clockwise direca tion about pivot l8. The limiting movement of the toggle comprising links2-2 and 23 is deter mined by an extension 29 on'link'22 'whichcooperates With a pin 30 on link 23 in a manner which is clearly obvious from Fig. 2;;

Rotatable about the axis of pivot 26. between the pair of links 23 and a U-shaped crank or lever- 27 is trip-latch roller 3i which is adapted to rest on a stop bo1t-32 supported from the plate E5, the proper height'of which ma beadjusted in arnanne'r which is obvious from the drawing. A suitable resetting spring 33 tendsto rotate lever 2'! in .3, counter-clockwise direction so that triplatch roller 3L tends -tobe in-engage-ment with stop bolt-325 It will be'obviousfrorna study of Figs. 2 and '3 thatif trip-latch roller Si is maintained in a fixed position against stpb01t32, a force appliedto toggleroller 25will cause rotation of operating crank H about pivot l8." If; however, trip-latchroller 31 1s free to'move away from stop bolt 32, then the'thrust-transmitting linkage collapses toward the rig-ht and rotation of operating crank l Twill-not occur-forthe-togglelinks 22 and 23 straighten out to cause crank 27 t'o' rotate clockwise against the bias ofits resetting spring 33. In order to hold trip-latch roller 31 against stop bolt 32;:therebyto control the collapsible linkage; there is p'rovided atrip-latch M pivotally mounted at: 35iltosid'e: plates-'13 and M A triplatch spring 3.6 biases trip lat'ch 3 lto the position indicated in Figs. 2 and 3 against stop 31? In this position trip-latch 34-.- hol'ds trip-latch roller 31 in a fixed position against stop'bolt 32 A suitable trip-coil"38 positioned in the manner disclosed and claimedin .Thumim' Patent 13882237,"granted January1 -1'5gi1935i' andi assigned to- -the same as signee: as the present application, :is' provided. When the plunger 39.:fassociated with trip-coil 38 1 isxmoved to the dotted position. indicated in Fig- 2,trip-latch 3.1iLis-rotated so that trip-latch roller 31 1's free. tomove with lever 2TB about pivot '28 causing collapse of the collapsible linkage 2st;

In order to restrain the collapsible linkage 21" in.therthrust-transmitting breaker-closed position indicated in Fig. 2, a pivotally mounted prop--4fi is provided rotatable about a shaft M supported between side plates I3; and- I4: A suitable-spring 42 biases'prop 4i! in-a-clockwise direction against a stop 43. .When. the. collapsiblealinka'ge .12=ta-is moved to the position indicatedin-Fi'g; 2. by p1ung-- er l2 prop 40. moye'sunder the extension. 2420i theeshaft forming the; knee ofcthe. toggle comprise ing. links 22- and- -235' tOyhOldf the linkageminrthe thrust-transmitting position-even though plunger; I2 returns. to the position indicated i in Fig.5 1.

Intorder to. cause highuspeed .openingqoi the circuit breaker i, circuit breakerv openingsprings are usually provided which in addition require buffer or dashpot means'tocushion the opening movement near the end of theopen-ing stroke to prevent damage to the'mechanism: In. accord:- ance: with. mywinvention Iprovidea combined opening. spring and-.bufiing device general-lyindie ing spring and huffing device of my invention com-f prises'z a cyliridribal housing 4'5 having: integral extensions w fo'rming a'yoke. This yoke'is pivotally mounted between side plates [3 and 14. Each oi the side plates is provided with a swivel pin Alengaging ans-opening 41 in the associated integ rali-jextension 46' of cylindrical housing 65;

Swivel pins 41 are really extensions of bolts threadedly -mountedin plates l3and l4 as is clearlyshownin Fig. 4. A suitable guide rod 48 extends through an opening in cylindrical housing-rdfit-andtthe-lowen end thereof is pivotally con-3 nected to operating crank I! and link 22 as indicated-at 2B. The cylindrical housing .45 with the integral extensions 46 forms a base from which the innenki'ck-ofi. spring hand the outersiolldwupispring 5& bias. the: crank I T an-d:.conseduently the-:c-ircui-tbreaker: ttothe open position'byrexert-i ing adownward-i opening :forc'e againsttthei guide rod crossheadii l2; In; this; mannenctheropening springs. .49: and; .5 exert a; force directly: against operating crank i1 and during .theEo-peration of thenopeningrsprings 1thei pivoted yoke comprising elements; dds-and; 436i is: free to 'SWillQflHi itszpiuot bearings-1n]; accordance with :the. angular: movement: of guide. rod l-fioso that. the springdoree will always .beapplied; in its most .efi-cientrmamaerz Within :cylindricaldiousing 45am stackedvsuite able bufiing. ,elements; such: as springs washers:

leather disks, andvwashers of ,otherzsuitable -shock absorbing materials. These :buffin'g elements are generally indicated: at: 5'2; and-are 'providedawi-th central openings through which; guide rod: 4E8? can extend. On top; of thel bufling; element is a striker plate 53 also provided with a centralionening through which guide rod 48 can extend. AJretainer. ring; 5 51% positioned in a; recess .55 :within cylindrical housing 45. maintains-the. striker plate 1 53 ande'bufi'ing; elements 5.2.- .in-the, position.= aind-icated the. drawing. Thewend' :of .gu-ide.-rod; 4-8

is threaded and provided with a paireofcstop uts 5.6. wh-ich: engage. striker flatev 5.3.- nean the end; of the opening. stroke: whereupon; the bruflingg-elenents. cushion thefin-a'lopening movementp f the operating mechanism.- It will be-observedythat the combinedwbufiing and opening. springirdevice makes a: convenient bench assembled. ,:uni:t;:for easyin sta1lati0n"and removalby means: of the swivel pins 4% which; screw intaside plates-i3. and I4;

In. view of the detailed description included,

above, the operation-citric circuit:breaken'operate ing-:-mechan-ismz of ray-invention will: :be obvious to those skilled in the;- art. ..-Withthe.-circuit breaker: in thencloseda position,., as. indicateddn Fig 1', energiza-tiorriofp trips; coil "38 permit. tript-latchl-rol-ler 3 I to move away: fromtstcn bolt 32 whereupon the extension Mofathe toggliezpivotl shaft moves oiffromrprtrp lilrvdth the consequent collapse; toward}. the right. oivthe: linkage-1212 that I finally-1 resets to the positiomind-icatedein Eigr: 3:

The. opening spri-ngs-,-e iq-wand" fiihiactingi against.

cross; head;512;,while:causingztherapidi collapse of. the-linkage 2.t;.-at the sameztimeswilr'irotate;one,

erating crankrllitoi cause-highspeemopeningiofi NGQLT-th$2BIIdOfSth6 opens:

the; circuit breaker-l ing stroke stOpJnuts. Baa-on-tguideirow ltaiengage striking plate 5.3."ofethe bufifingadecice whereupon circuit breaker is obtained by energization of solenoid it which causes plunger 52 to move up from the position indicated in Fig. 3 to the position indicated in Fig. 2 with the consequent thrust-transmitting movement of the linkage 2! to its latch-restrained position of Fig. 2. This operation causes rotation of operating crank i7 and recharging of opening springs d9 and During both the opening and closing operation the combined opening spring and bufing device i -l is free to pivot about swivel pins ti.

My new and improved operating mechanism may readily be applied to various circuit breakers and the desired high speed opening operations and cushioning operation of the circuit breaker which are inherent in my device, will be automatically supplied to the circuit breaker.

It should be understood that my invention is not limited to specific details of construction and arrangement thereof herein illustrated, and that changes and modifications may occur to one skilled in the art Without departing from the spirit of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An arrangement for imparting opening force to a pivotally mounted main operating member of an electric circuit breaker to open said circuit breaker and for arresting the opening operation of said circuit breaker comprising a pivotally mounted yoke member, a rod pivotally connected to said main operating member and slidable through an opening in said yoke member, spring means interposed between said yoke member and said main operating member for biasing said circuit breaker to the open position, said yoke member being movable about its pivotal support in such a way that the bias of said spring means is effective throughout the opening operation of said circuit breaker, cushioning material mounted on said yoke member, and a projection on said rod for engaging said cushioning material near the end of the opening operation of said circuit breaker.

2. An arrangement for imparting opening force to a pivotally mounted main operating member of an electric circuit breaker to open said circuit breaker and for arresting the opening operation of said circuit breaker comprising a pivotally mounted yoke member, a plurality of shock absorbing apertured discs mounted in said yoke member, a rod pivotally connected at one end thereof to the main operating member and slid able through an opening in said yoke member and through the apertures in said discs, a projection on the opposite end of said rod for engaging said shock absorbing discs near the end of the opening operation of said circuit breaker, and spring means interposed between said yoke member and said main operating member for biasing said circuit breaker to the open position.

3. An arrangement for imparting opening force to a pivotally mounted main operating member of an electric circuit breaker to open said circuit breaker and for arresting the opening operation of said circuit breaker comprising a pivotally mounted yoke member, a plurality of yieldable apertured discs mounted in said yoke member, a rod pivotally connected at one end thereof to the main operating member and slidable through an opening in said yoke member and through the apertures in said discs, a projection on the opposite end of said rod for engaging said yieldable discs near the end of the opening operation of said circuit breaker, and a plurality of compression springs interposed between said yoke member and said main operating member and surrounding said rod for biasing said circuit breaker to the open position.

RALPH J. BASKERVILLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 843,070 Button Feb. 5, 1907 962,958 Hewlett June 28, 1910 1,190,060 Wolff July 4, 1916 1,739,917 Rayzor Dec. 17, 1929 1,827,626 Thumim Oct. 13, 1931 1,841,162 Thumim Jan. 12, 1932 1,900,289 Kelly et a1 Mar. 7, 1933 2,222,146 Jonsson Nov. 19, 1940 2,387,266 Holland Oct. 23, 1945 

